In U.S. Pat. No. 3,275,626 issued Sept. 27, 1966 Morin and Jackson disclose the formation of cephalosporin compounds having an exocyclic double bond in the 3-position of the cepham ring system. Subsequently, in my copending application Ser. No. 118,941 filed Feb. 25, 1971 now U.S. Pat. No. 3,932,393 issued Jan. 13, 1976 the preparation of 3-exomethylenecepham compounds with 3thio-substituted-methylcephalosporins is described. For example, cephalosporins substituted on the 3'-methyl group with tioureas (isothiouronium salts) are reduced under hydrogen in the presence of Raney nickel or with zinc and formic acid in the presence of dimethylformamide to provide the 3-exomethylenecepham compounds.
More recently in my copending application Ser. No. 310,191 filed on Nov. 28, 1972 now U.S. Pat. No. 3,917,587 issued Nov. 4, 1974 the oxidation of 3-exomethylenecepham esters with ozone is described. The predominant product of the ozonolysis described therein is the 3-hydroxy-3-cephem ester which is reacted with a diazoalkene to provide the corresponding ester of a 3-alkoxy-3-cephem. Removal of the ester group provides the alkoxylated antibiotic compound. For example, 7-phenoxyacetamido-3-hydroxy-3-cephem-4-carboxylic acid p-nitrobenzyl ester, obtained by the ozonolysis of the corresponding 3-exomethylene compound, is reacted with diazomethane to form p-nitrobenzyl 7-phenoxyacetamido-3-methoxy-3-cephem4-carboxylate. The p-nitrobenzyl ester group is removed by catalytic hydrogenolysis in the presence of 5% palladium on carbon catalyst to provide the free carboxylic acid antibiotic compound. In the same application Ser. No. 310,191, the formation of 3-exomethylenecepham-4-carboxylic ester sulfoxides and 3-hydroxy-3-cephem-4-carboxylic acid ester sulfoxides are disclosed as side products of the ozonolysis reaction of 3-exomethylenecepham esters.
This invention relates to 7-acylamido-3-exomethylenecepham-4-carboxylic acid and ester sulfoxides and 7-acylamido3-hydroxy-3-cephem-4-carboxylic acid ester sulfoxides.